Manila- The World Health Organization (WHO) vowed on Friday to intensify the fight against malaria in Asia and the Pacific amid growing signs of the disease developing greater resistance to commonly used drugs.

The Manila-based WHO Western Pacific Office expressed concern over the situation in the Thai-Cambodian border where a strain of malaria that is increasingly resistant to artemisinin, the most effective drug available to fight the disease, has proliferated.

"Time is of the essence here. We have to act now to contain this problem within the Mekong region. It must not be allowed to spread and become a regional and international threat," said Shin Young-Soo, WHO regional director for the Western Pacific.

"Measures such as early malaria diagnosis, effective treatment and high quality surveillance need to be maintained and funding sustained," Shin added. "New tools will need to be developed if malaria elimination is to be achieved through the region."

WHO also expressed concern over the rampant use of low-quality and counterfeit drugs in some countries in the Mekong region and the improper use of medicines such as antibiotics and antimalarials, including arteminisin.

WHO said it is closely working with the Bill and Melinda Gates Foundation and other donor agencies to contain the drug-resistant malaria in the Mekong region.

The initiative is part of a global anti-malaria programme called "Counting Malaria Out" which will kick off Saturday with the aim of achieving near-zero deaths from the mosquito-borne disease by 2015.

Among the malaria-endemic countries in Asia and the Pacific are Cambodia, China, South Korea, Malaysia, Laos, Papua New Guinea, the Philippines, the Solomon Islands, Vanuatu and Vietnam.

WHO said that every year, there are 250 million cases of malaria infections around the world, causing nearly one million deaths. In the the Western Pacific region, more than 300,000 malaria cases were confirmed in 2007, with 939 deaths. (dpa)